Corner joint



Oct. 7 1924. 1,510,503

- J. c. SCHMIDT CORNER JOINT Filed Feb. 5, 1920 Patented Get. 7, 1924.

OFFICE.

JOHN c. scrnarnrr, on sat. LOUIS, MISSOURI, iissrenon T0 Hnvrsnnr' AND FREDERICK c. SCHMIDT, TRUSTEES.

CORNER JOINT.

Application filed February 3, 1920. Serial 'No. 355,919.

To all whomit may concern:

Be it known that I, J OHN C. SCHMIDT, a citizen of the United States, residing at the city of St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Corner Joints, of which the following is a specification.

This invention is a metallic corner-joint for curtain-stretcher frames or the like, and its merits reside in its being of integral onepiece construction, whereby greater rigidity is imparted to assembled curtain-stretcher frames. Moreover, being formed of sheet metal in one piece, it can be produced very cheaply, as is necessary in such uses, as it can be simultaneously stamped, punched, and pressed, and thus formed complete at one operation.

Curtain-stretcher frames are necessarily rather lengthy, in order to accommodate the length of lace curtains and the like. It is not practical or desirable to make such frames permanent and thereby rigid. It is preferable that they shall be normally in knocked-down condition and assembled only for use. on account of their size, they are anunusually wobbly construction. A onepiece corner-joint that receives and holds within its one-piece grip the sides and ends, which project at a right angle from each other, is a highly useful and desirable de- Vice, and is provided by this invention.

In the accompanying drawings forming part of this specification, in which like numbers of reference denote like parts wherever they occur,

Figure 1 is a plan view of a curtainstretcher frame showing this device holding its members at its four corners;

Figure 2 is a perspective view of this device detached from the frame;

Figure 3 is a side elevation of this device showing either end or side of frame in section and the member at a right angle thereto fragmentarily in elevation;

Figure 4 is a view taken at a right angle to Figure 3;

Figure 5 is a plan View of this device; and

Figure 6 is an opposite plan view of the same.

In speaking of this device, the terms top and bottom plan View and side and rear elevation are only relative terms, as it looks the same from the bottom as the, top and from the rear as from the side. I The bolt 1 and the bolt 2 are interchangeable and reversible. Thus, the bolt 1, while shown in Figure 3 with its head 3' at the right of the figure and the butterfly nut 4 at theopposite side of the device, can be reversed in their relation to the device; In Figure 4: the head 5 of bolt 2 is shown at the left of the figure and the butterfly nut 6 at the right, but this order of arrange ment can be reversed.

Likewise, bolt 1 can be substituted in use for bolt 2,.and vice versa. T

Examination of Figure 1 will demonstrate that the frame 7 is'bound to be rigid when its longitudinal members are tightly gripped by passing in one direction through a cornerjoint like this, while the connecting transverse member passes through and is tightly gripped at a right angle thereto by the same corner-joint. This would not'be true if the corner-joint were" not a onepiece membcr and if it were not itself of suflicient strength and rigidity to hold firmly the members that are arranged at an angle to each other and that constitute the frame 7.

The said corner-joint can be formed from a one piece blank or can be stamped from sheet metal, and its shape imparted to it by pressure, whereby, after stamping and pressing, it comprises the web 8 and the pair of projections 9 and the pair of projections 10. In the uprights 9 are formed recesses 11 having the shoulders or lips 12, whereby'the frame member passing between the pair of projections'or uprights 9 is tightly held between the said projections 9 and underneath the said lips 12. The projections 10 are similarly constructed, having the recesses 13 and lips 14, whereby the member of frame 7 running at a right angle to the one held between projections 9 is likewise held in place. The bolts 1 and 2 with their respective heads 3 and 5 and butterfly nuts 4 and 6 keep the projections 9 and 10 from spreading, and even draw the same into tighter engagement with the frame members passing I ill vide convenient handles or grips by which the stretcher frame may be lifted and moved, when desired, the spacing of the outer ends of the projections being such as to readily permit the bolts to be easily grasped.

Thus is provided a curtain-stretcher frame 7 composed of a plurality of parts arranged at a right angle to each other and joined at their connections by integral one-piece corner-joints, each comprising a web and a pair of projections extending therefrom in one direction and another pair of projections extending therefrom in the opposite direction and at a right-angle to the plane of the said first-mentioned projections, each of the said projections having on its inner face a gripping shoulder, and each of the said projections having a bolt-hole therethrough, and there being bolts passing through the said bolt-holes, each of the said bolts having a head and a nut thereon, and the said framemembers passing through the said cornerjoints in such way that one is gripped between one of the said pairs of projections and their shoulders and another at a right angle thereto being gripped by the other of the said pairs of projections and the shoulders on their inner faces.

It will be particularly noted that the lips 12 and 14 of the respective sides of the joint, are clamped along the longitudinal edges of the respective curtain-stretcher strips, and that the clamping bolts are spaced some distance from the surface of sguclt strips. This leaves the larger portion of each stretcher strip fully exposed between the lips, to thereby avoid interference with the usual holding pins of such strips. This permits the joint to be used at any point lengthwise any of the stretcher strips, as may be desired. As illustrated in Figures 2 and 3, the inwardly extending offsets 12 which define the frame engaging shoulders also define pairs of apertured ears through which the fastening bolts 1 and 2 are extended. When the nuts 4- and 6 are tightened the inner portions of the offsets are forced into the faces of the strips forming the frame so that the device is securely held in position. In other words, the tightening of the nuts and 6 will cause the ears through which the bolts are extended to tilt slightly whereby the meeting portions of the ears and the shoulders are forced inwardly into the wood of the frame.

Having thus described this invention, I hereby reserve the benefit of all changes in form, arrangement, order, or use of parts, as it is evident that many minor changes may he made therein without departing from, the spirit of this invention or the scope of the following claim.

I claim:

, A corner joint for connecting rectangular nembers crossing each other at right angles comprising ametal blank having an intermediate portion or web adapted to be interposed between adjacent faces of the members, and oppositely directed pairs of integral projections extending from the web to embrace the said members on opposite sides, the projections of each pair being spaced apart at their outer ends for practically the full width of the member embraced therebetween, a bolt spanning the distance between the said spaced ends and supported thereby in outwardly spaced relation to the underlying member to provide a handle, said bolt having a headed end supported in one projection and a threaded terminal supported in the other projection, and a thumb screw engaging the threaded terminal beyond the projection.

In testimony whereof I hereunto affix my signature.

JOHN C. SCHMIDT 

